E39 540i m62b44 STOP ENGINE PRESSURE!

[540ipapasmurf]

Hello everyone... For several months, my car has been giving oil pressure warning after warm engine below 1 rpm. This began after regular maintenance of thermostat (BEHR) changing. After months of trying and searching on forums, one user stated that it happened to him on a new thermostat from BEHR and once he changed it, engine ran better. I threw in so much stupid money to stop this problem and now placed a thermostat from e31 840ci for Gulf countries. My problem finally went away! So, if oil pressure switch isn't your solution, if oil filter housing isn't your solution, and if oil pump bolts isn't your solution then PLACE THE THERMOSTAT. Also, before i changed to 85c thermostat, my engine would go up to 117c in traffic. Now it goes maximum 91c. Amazing!

To people out there who will have this problem in the future. Listen to me and get cooler thermostay. Peace.

Sent from my Mi Note 10 Lite using Tapatalk

[JimLev]

Typo? Did you mean 1000 RPM?

[ross1]

I suspect that your cooling system might otherwise be marginal, or that Behr stat was NG as 117*c is pretty damn hot. At that temp any functioning thermostat would(should) be wide open.
I wonder what oil temps were.
Possibly a different(better) oil would also mitigate the thinning when hot.

[E39 Newbie]

117C??? That's pushing 250F! That should have been your first clue that you had a bum thermostat. By the way, what oil is available in your country?

[TiesTorN]

it was probably a bad tstat. shouldn't exceed 108c with the OE one. oil becomes too thin at 117c+ that's probably why u were seeing that warning. I hope you didn't damage the engine.

[ross1]

117C??? That's pushing 250F! That should have been your first clue that you had a bum thermostat. By the way, what oil is available in your country?

Yeah. So much for these weak cooling systems exploding